Nanotube signal transmission system

ABSTRACT

A method and apparatus for transmitting signals. An apparatus comprises a tube comprising a number of layers of carbon forming a wall of the tube. The number of layers of carbon has a number of optical properties configured to propagate an optical signal and a number of electrical properties configured to conduct an electrical signal.

CROSS-REFERENCE TO RELATED CASE

This application is related to the following patent application:entitled “Devices for Communicating Optical Signals and ElectricalSignals Over Nanotubes”, Ser. No. 13/482,691; filed even date hereof,assigned to the same assignee, and incorporated herein by reference.

BACKGROUND INFORMATION

1. Field

The present disclosure relates generally to transmitting informationand, in particular, to transmitting optical signals and electricalsignals. Still more particularly, the present disclosure relates to amethod and apparatus for transmitting optical signals and electricalsignals using nanotubes.

2. Background

In aircraft, satellites, vessels, submarines, vehicles, powertransmission lines, communication lines, and other situations, reducingthe size and weight of equipment is desirable. For example, reducing theweight and size of communications links used to transmit signals may bedesirable. These communications links may transmit information, power,or both information and power. Electrical wires are commonly used inaircraft and other mobile platforms, as well as power transmissionlines, communication lines, and other environments to transmit signalsbetween various devices.

The wires and insulation used to form the communications and/or powerlinks may be heavier than desired. Further, as the number of wiresincrease, the space needed for the wires may increase more than desired.

One alternative involves using communications links formed throughoptical fibers. An optical fiber is a flexible, transparent fiber thatmay be made of a material such as silica. One or more of these opticalfibers may be placed in a cladding with a sheath around the cladding toform an optical fiber cable. Optical fiber cables may be much thinnerand lighter as compared to wires used to carry electrical signals.However, optical fibers may still have a size and weight that is greaterthan desired.

Therefore, it would be desirable to have a method and apparatus thattakes into account at least some of the issues discussed above, as wellas other possible issues.

SUMMARY

In one illustrative embodiment, an apparatus comprises a tube comprisinga number of layers of carbon forming a wall of the tube. The number oflayers of carbon has a number of optical properties configured topropagate an optical signal and a number of electrical propertiesconfigured to conduct an electrical signal.

In another illustrative embodiment, a communications system comprises anetwork and a number of devices. The network is comprised of graphenenanotubes configured to transmit optical signals and electrical signalswithin the network. The number of devices is configured to exchangeinformation using at least one of the optical signals and the electricalsignals.

In still another illustrative embodiment, a method for transmittingsignals is present. At least one of an optical signal and an electricalsignal are transmitted using a tube comprised of a number of layers ofcarbon forming a wall of the tube. The number of layers of carbon has anumber of optical properties configured to propagate the optical signaland a number of electrical properties configured to conduct theelectrical signal.

The features and functions can be achieved independently in variousembodiments of the present disclosure or may be combined in yet otherembodiments in which further details can be seen with reference to thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the illustrativeembodiments are set forth in the appended claims. The illustrativeembodiments, however, as well as a preferred mode of use, furtherobjectives and features thereof, will best be understood by reference tothe following detailed description of an illustrative embodiment of thepresent disclosure when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is an illustration of a block diagram of an informationenvironment in accordance with an illustrative embodiment;

FIG. 2 is an illustration of a block diagram of a communications link inaccordance with an illustrative embodiment;

FIG. 3 is an illustration of a block diagram of a tube in accordancewith an illustrative embodiment;

FIG. 4 is an illustration of a block diagram of a device in accordancewith an illustrative embodiment;

FIG. 5 is an illustration of a layer of carbon that may be used in acommunications link in accordance with an illustrative embodiment;

FIG. 6 is an illustration of a tube formed from a layer of graphene inaccordance with an illustrative embodiment;

FIG. 7 is an illustration of an end of a nanotube in accordance with anillustrative embodiment;

FIG. 8 is an illustration of a communications link in accordance with anillustrative embodiment;

FIG. 9 is an illustration of an end of a communications link inaccordance with an illustrative embodiment;

FIG. 10 is an illustration of different orientations for layers ofcarbon that may be selected to form different types of nanotubes inaccordance with an illustrative embodiment;

FIG. 11 is an illustration of a multi-walled nanotube in accordance withan illustrative embodiment;

FIG. 12 is an illustration of devices connected to each other throughnanotubes in accordance with an illustrative embodiment;

FIG. 13 is an illustration of devices powered by Hall Effect devices inaccordance with an illustrative embodiment;

FIG. 14 is an illustration of a flowchart of a process for transmittingsignals in accordance with an illustrative embodiment;

FIG. 15 is an illustration of a flowchart of a process for transmittinga signal in accordance with an illustrative embodiment; and

FIG. 16 is an illustration of a flowchart of a process for transmittinga signal in accordance with an illustrative embodiment.

DETAILED DESCRIPTION

The illustrative embodiments recognize and take into account one or moredifferent considerations. For example, the illustrative embodimentsrecognize and take into account that carbon nanotubes may be used inplace of optical fibers. These carbon nanotubes may be much thinner indiameter as compared to an optical fiber. For example, an optical fibermay have a diameter from about 0.25 millimeters to about 0.5millimeters. In contrast, a nanotube may have a diameter of about 1nanometer, although the diameter may vary. In other words, an opticalfiber that is about 0.5 millimeters thick is about 500,000 times thickerthan a nanotube having a diameter of about 1 nanometer.

The illustrative embodiments recognize and take into account that acarbon nanotube may be selected to have properties to propagate opticalsignals through a channel in the nanotube. In this manner,communications links formed using carbon nanotubes may be lighter inweight and take up less space as compared to optical fibers.

Further, the illustrative embodiments also recognize and take intoaccount that oftentimes, devices within a communications system may usedifferent types of signal propagation. For example, the illustrativeembodiments recognize and take into account that some devices may useoptical signals, while other devices may use electrical signals. As aresult, an aircraft or other platform in which communications links areimplemented may use both wires and optical fibers. With these designs,some of the weight and size savings from optical fibers may be lost.Additionally, the designs for these communications systems take intoaccount the devices that may be used within the communications system.If devices may be interchanged that use different types of signalpropagation, then both a wire and an optical fiber need to be present.The presence of both types of communications links for increasedflexibility may further increase the size and weight of thecommunications links beyond what is desirable.

The illustrative embodiments also recognize and take into account thateven when optical fibers are used, additional wires may be needed toprovide power to the devices because currently used optical fibers areunable to carry power. Optical cables may include a conductive sheath ora wire in addition to the optical fibers that conduct electricalsignals. These electrical signals may be used for information and power.Optical fibers that include these components, however, may be thickerand heavier than desired.

Thus, the illustrative embodiments provide a method and apparatus fortransmitting signals of different types within a single communicationslink. In these illustrative examples, an apparatus comprises a tube thatis comprised of a number of layers of carbon forming a wall. The numberof layers of carbon has a number of optical properties configured topropagate an optical signal and a number of electrical propertiesconfigured to conduct an electrical signal. In this manner, the samecommunications link may be used to transmit both types of signals.Further, the communications link also may be used to transmitinformation in an optical signal while transmitting power in anelectrical signal for a device.

With reference now to the figures, and in particular, with reference toFIG. 1, an illustration of a block diagram of an information environmentis depicted in accordance with an illustrative embodiment. In thisdepicted example, information environment 100 includes communicationssystem 102.

Communications system 102 may be used to transmit information 103. Thisinformation may take a number of different forms. For example,information 103 may be images, data, video, programs, commands, voice,and other types of information.

Communications system 102 may be associated with platform 104. When onecomponent is “associated” with another component, the association is aphysical association in these depicted examples. For example, a firstcomponent, communications system 102, may be considered to be associatedwith a second component, platform 104, by being secured to the secondcomponent, bonded to the second component, mounted to the secondcomponent, welded to the second component, fastened to the secondcomponent, and/or connected to the second component in some othersuitable manner. The first component also may be connected to the secondcomponent using a third component. The first component may also beconsidered to be associated with the second component by being formed aspart of and/or an extension of the second component.

As used herein, a “number of” when used with reference to items meansone or more items. For example, a number of forms is one or moredifferent forms. As another example, a number of layers of carbon maymean a single layer of carbon.

In these illustrative examples, platform 104 may take a number ofdifferent forms. For example, without limitation, platform 104 may be amobile platform, a stationary platform, a land-based structure, anaquatic-based structure, and a space-based structure. More specifically,platform 104, may be a surface ship, a tank, a personnel carrier, atrain, a spacecraft, a space station, a satellite, a submarine, anautomobile, a power plant, a bridge, a dam, a manufacturing facility, abuilding, a telephone communications system, a cable television network,and undersea cable, a high power transmission system, a communicationssystem, and other suitable platforms.

As depicted, communications system 102 comprises network 106 and devices108. In these illustrative examples, devices 108 are hardware devices.Devices 108 may take a number of different forms. For example, devices108 may include at least one of computers, tablet computers, sensors,actuators, repeaters, switches, routers, network nodes, and othersuitable types of devices.

As used herein, the phrase “at least one of”, when used with a list ofitems, means different combinations of one or more of the listed itemsmay be used and only one of each item in the list may be needed. Forexample, “at least one of item A, item B, and item C” may include,without limitation, item A or item A and item B. This example also mayinclude item A, item B, and item C, or item B and item C. In otherexamples, “at least one of” may be, for example, without limitation, twoof item A, one of item B, and ten of item C; four of item B and seven ofitem C; and other suitable combinations.

Network 106 is comprised of communications links 110. Communicationslinks 110 are hardware links in these illustrative examples.Communications links 110 are configured to carry optical signals 112,electrical signals 114, or both optical signals 112 and electricalsignals 114 at the same time. Devices 108 may operate using opticalsignals 112, electrical signals 114, or both optical signals 112 andelectrical signals 114.

In these illustrative examples, information 103 may be exchanged bydevices 108 using optical signals 112, electrical signals 114, or both.Additionally, power 118 may be supplied to a portion of devices 108through electrical signals 114 transmitted within network 106 incommunications system 102 in these illustrative examples. In otherwords, one or more of devices 108 may receive power from network 106. Inother illustrative examples, power 118 also may be supplied throughoptical signals 112. Thus, power 118 may be supplied using at least oneof optical signals 112 and electrical signals 114.

Turning now to FIG. 2, an illustration of a block diagram of acommunications link is depicted in accordance with an illustrativeembodiment. In this depicted example, communications link 200 is anexample of a communications link in communications links 110 in FIG. 1.

As depicted, communications link 200 includes number of tubes 202.Number of tubes 202 may be configured to provide a desired index ofrefraction for optical signals 112 in FIG. 1. Number of tubes 202 may bea single tube. In other words, a number of additional tubes may bepresent in addition to the tube when number of tubes 202 includes morethan one tube.

Each tube in number of tubes 202 may be covered by number of sheaths204. When more than one tube is present in number of tubes 202, thenumber of additional tubes may be further covered by cover 206.

As depicted, a sheath in number of sheaths 204 is an insulating sheath.Number of sheaths 204 may provide insulation for electrical signals inthese illustrative examples. Additionally, number of sheaths 204 alsomay be configured to provide a desired index of refraction for opticalsignals 112 in FIG. 1 that may pass through walls in number of tubes202. Further, number of sheaths 204 may be configured to provide opticalabsorption of stray photons that pass through the walls at an incidencethat is greater than the index of refraction.

Turning now to FIG. 3, an illustration of a block diagram of a tube isdepicted in accordance with an illustrative embodiment. In thisillustrative example, tube 300 is an example of a tube in number oftubes 202 for communications link 200 in FIG. 2.

In these illustrative examples, tube 300 is comprised of number oflayers of carbon 302 that form wall 304. Channel 306 extends throughtube 300. As depicted, number of layers of carbon 302 may take the formof number of layers of graphene 308. In other words, tube 300 may be agraphene tube and, more specifically, may be a graphene nanotube. Thus,network 106 may be comprised of graphene nanotubes used to exchangeelectrical signals between a number of devices 108 in communicationssystem 102.

Number of layers of carbon 302 may be, for example, one, two, three, orsome other suitable number of layers. In other words, number of layersof carbon 302 for tube 300 may be a single layer of carbon. In someillustrative examples, tube 300 may include a number of additionallayers of carbon in addition to the layer of carbon when number oflayers carbon 302 includes more than one layer.

In these illustrative examples, number of layers of carbon 302 that formtube 300 have number of optical properties 310 and number of electricalproperties 312. Number of optical properties 310 for number of layers ofcarbon 302 is configured to propagate optical signal 314. Number ofelectrical properties 312 for number of layers of carbon 302 isconfigured to conduct electrical signal 316. In these illustrativeexamples, both optical signal 314 and electrical signal 316 may travelthrough tube 300 at substantially the same time. Optical signal 314 isan example of an optical signal in optical signals 112 in FIG. 1.Electrical signal 316 is an example of an electrical signal inelectrical signals 114 in FIG. 1.

Number of optical properties 310 may include an index of refraction. Forexample, the index of refraction may be higher or lower than air,vacuum, or the index of refraction of some other medium in channel 306in which index of refraction allows channel 306 within tube 300 to actas a hollow core in an optical fiber. In other words, channel 306 mayinclude a material through which photons propagate in some illustrativeexamples.

The index of refraction may be controlled through parameters, such asthe density of the nanotubes. In one illustrative example, the densitymay be the density of the tube, the number of tubes within a givenvolume, or both. The index of refraction may control the relativealignment of the tube with respect to each other.

Resistivity, impedance, capacitance, and conductivity are examples ofelectrical properties in number of electrical properties 312. In theseillustrative examples, a lower resistivity or higher conductivity isdesired. In particular, the resistivity is selected to be low enough toconduct electrons in a desired manner.

In these illustrative examples, optical signal 314 may propagate throughchannel 306 inside tube 300. As depicted, optical signal 314 may havevarious wavelengths. These wavelengths may be for visible light,infrared light, ultraviolet light, or other wavelengths. For example,the wavelengths for optical signal 314 may be from about 10 nanometersto about 400 micrometers.

Electrical signal 316 may propagate along wall 304 of tube 300.Propagation of electrical signal 316 may be along inner surface 318 ofwall 304, outer surface 320 of wall 304, or both.

As depicted, tube 300 is configured to transmit information 322 in atleast one of optical signal 314 and electrical signal 316. Additionally,tube 300 also is configured to transmit power 324 using at least one ofoptical signal 314 and electrical signal 316.

In some illustrative examples, different layers in number of layers ofcarbon 302 may have various orientations. These orientations may havedifferent angles and may form at least one of zigzag nanotubes, armchairnanotubes, and chiral nanotubes. These different types of orientationsfor number of layers of carbon 302 may be selected to modify theelectrical, optical, and or chemical properties of tube 300.

Further, additional number of layers of other materials may be added totube 300 to modify the electrical, optical, and or chemical propertiesof tube 300. For example, one or more layers of carbon, graphene, orother materials may be added to form insulation, create inductance,create capacitance, modify the index of refraction, protect the tubefrom chemical changes, and/or for other purposes.

With reference now to FIG. 4, an illustration of a block diagram of adevice is depicted in accordance with an illustrative embodiment. Inthis depicted example, device 400 is an example of a device withindevices 108 in FIG. 1.

In these illustrative examples, device 400 may communicate using atleast one of an optical signal and an electrical signal through aconnection through a tube. As depicted, device 400 includes at least oneof receiver 402 and transmitter 404.

Receiver 402 and transmitter 404 are hardware and may include software.Receiver 402 and transmitter 404 may be implemented using circuits.These circuits may be configured to generate or process electricalsignals, optical signals, or both electrical signals and opticalsignals. For example, transmitter 404 may include an encoder to encodeinformation in an electrical signal. In a similar fashion, receiver 402may include a decoder to retrieve information from an electrical signal.

In this illustrative example, receiver 402 is in communication with tube406, while transmitter 404 is in communication with tube 408. Tube 406and tube 408 may be a tube such as tube 300 in FIG. 3. In particular,tube 406 and tube 408 may be in the same communications link in theseillustrative examples. For example, tube 406 and tube 408 may be tubesin number of tubes 202 in communications link 200 in FIG. 2. In otherillustrative examples, these two tubes may be in separate communicationslinks.

In this illustrative example, receiver 402 is configured to receiveoptical signal 410 and electrical signal 412 through tube 406.Transmitter 404 is configured to transmit optical signal 414 andelectrical signal 416 through tube 408.

In these illustrative examples, the optical signals and the electricalsignals may be sent and/or received at substantially the same time. Forexample, optical signal 410 and electrical signal 412 may be receivedthrough tube 406 at the same time. In a similar fashion, optical signal414 and electrical signal 416 may be transmitted through tube 408 at thesame time.

In some illustrative examples, electrical signal 412 may be used toprovide power for one or more circuits within device 400. For example,electrical signal 412 may be configured to provide power to at least oneof receiver 402 and transmitter 404 as well as one or more of circuits418. Circuits 418 may take various forms. For example, circuits 418 mayinclude at least one of an amplifier, a buffer, a memory, a processorunit, and other suitable types of circuits.

In these illustrative examples, information may be transmitted using atleast one of both optical signal 414 and electrical signal 416. Whenboth optical signal 414 and electrical signal 416 are used to transmitinformation, these signals may be transmitted at the same time throughtube 408.

In some illustrative examples, device 400 may also include power supply420. Power supply 420 may be used to send power using electrical signal416. Power supply 420 may take various forms. For example, power supply420 may be a generator that generates electrical energy from other formsof energy. In other illustrative examples, power supply 420 may controlproperties of electrical signal 416 such as voltage, current, and othersuitable properties. For example, power supply 420 may convertalternating current to direct current or vice versa when sendingelectrical signal 416 using tube 408.

In other illustrative examples, power supply 420 in device 400 mayreceive electrical signal 412 and send electrical signal 412 todifferent circuits in device 400.

In other illustrative examples, power supply 420 may be used to derivepower from electrical signal 412 indirectly using the Hall Effect. Inaddition to using current in electrical signal 412 to provide power tocircuits within device 400, device 400 may derive power from electricalsignal 412 indirectly.

For example, power supply 420 may include magnetic field generator 422.In these illustrative examples, magnetic field generator 422 may includeat least one of a magnet, an electromagnet, and some other suitable typeof device.

Magnetic field generator 422 is configured to generate a voltagedifference between a first side and a second side of tube 406 whenelectrical signal 412 is received. A circuit, such as receiver 402,transmitter 404, or some other circuit in circuits 418 may be configuredto operate using the voltage difference. In this manner, device 400 mayderive power indirectly from electrical signal 412. Of course,electrical signal 412 also may be used directly to derive power fordevice 400. Electrical signal 412 may have a current used by circuitswithin device 400.

Additionally, magnetic field generator 422 also may be used with tube408 when transmitter 404 transmits electrical signal 416. In thisconfiguration, the voltage difference is present between a first sideand a second side of tube 408. This voltage difference also may be usedto power different circuits in device 400 such as at least one ofreceiver 402, transmitter 404, and circuits 418.

The illustration of information environment 100 and the differentcomponents in information environment 100 in FIGS. 1-4 are not meant toimply physical or architectural limitations to the manner in which anillustrative embodiment may be implemented. Other components in additionto or in place of the ones illustrated may be used. Some components maybe unnecessary. Also, the blocks are presented to illustrate somefunctional components. One or more of these blocks may be combined,divided, or combined and divided into different blocks when implementedin an illustrative embodiment.

For example, information environment 100 also may include communicationslinks that are comprised of wires and optical fibers. Further, in someillustrative examples, communications links 110 may include wirelesscommunications links.

Further, in other illustrative examples, communications system 102 mayspan across more locations than just platform 104. For example,communications system 102 may be a local area network, a wide areanetwork, an intranet, or some other suitable type of communicationssystem. Further, in other illustrative examples, communications system102 may be high voltage power transmission lines with inherent opticalcommunications signaling.

Turning now to FIG. 5, an illustration of a layer of carbon that may beused in a communications link is depicted in accordance with anillustrative embodiment. In this depicted example, layer of carbon 500is an example of a layer of carbon that may be used to form a tube suchas tube 300 shown in block form in FIG. 3.

In this illustrative example, layer of carbon 500 takes the form oflayer of graphene 502. Graphene is an allotrope of carbon. As depicted,layer of graphene 502 takes the form of a honeycomb lattice formed bycarbon atoms.

In these illustrative examples, layer of graphene 502 provides desiredelectrical properties for conducting an electrical signal. For example,layer of graphene 502 has desired levels of electron mobility at roomtemperature. For example, the mobility may be about 15,000 cm² v⁻¹ s⁻¹or greater. The resistivity of layer of graphene 502 may be about 10⁻⁶ohms/cm at room temperature.

Turning now to FIG. 6, an illustration of a tube formed from a layer ofgraphene is depicted in accordance with an illustrative embodiment. Inthis illustrative example, layer of graphene 502 from FIG. 5 is in theshape of tube 600. In this illustrative example, tube 600 takes the formof nanotube 602. Nanotube 602 has end 604 and end 606. Channel 608extends from end 604 to end 606 of nanotube 602.

Nanotube 602 has diameter 610. Diameter 610 may be, for example, about0.4 nanometers to about 40 nanometers. However, diameter 610 may be anydiameter depending on the implementation. For example, diameter 610 maybe larger than 40 nanometers. In some illustrative examples, diameter610 may be larger than normal for a nano structure.

In these illustrative examples, nanotube 602 has length 612. Length 612may vary. For example, length 612 may be about 18.5 centimeters.However, graphene is one of the strongest materials known and length 612may be any length that can be fabricated. Thus, length 612 also may begreater than about 18.5 centimeters. For example, length 612 may even beabout 1 meter, about 1 kilometer or some other suitable length.

Turning now to FIG. 7, an illustration of an end of a nanotube isdepicted in accordance with an illustrative embodiment. In this depictedexample, end 606 of nanotube 602 is depicted. In this illustrativeexample, wall 700 of nanotube 602 has inner surface 702 and outersurface 704.

As depicted, photons 706 for an optical signal may propagate throughchannel 608. As photons 706 propagate through channel 608, photons 706may reflect off of inner surface 702 of wall 700. As depicted, thewavelength of photons 706 may affect the index of refraction fornanotube 602.

In these illustrative examples, photons 706 may continue to reflect offof inner surface 702 of wall 700 as long as the angle between the vectorthat a photon travels along and inner surface 702 of wall 700 is notgreater than about 20 degrees. If the angle is greater than about 20degrees, the photon may pass through wall 700. Additionally, electrons708 may conduct along inner surface 702 of wall 700, outer surface 704of wall 700, or conduct along both inner surface 702 and outer surface704 of wall 700 for nanotube 602.

Depending on the length of nanotube 602, multiple nanotubes may bealigned with each other, bonded, or otherwise connected to each other toform a longer structure for a communications link. In other words, oneend of a nanotube may be connected to an end of another nanotube suchthat the channels in the two nanotubes are in communication with eachother.

Turning now to FIG. 8, an illustration of a communications link isdepicted in accordance with an illustrative embodiment. In this depictedexample, communications link 800 has end 802 and end 804. Communicationslink 800 is comprised of nanotubes 806, 808, 810, 812, 814, 816, and818. These nanotubes may be nanotubes such as nanotube 602 shown inFIGS. 6-7.

In this illustrative example, sheaths 820, 822, 824, 826, 828, 829 and830 cover nanotubes 806, 808, 810, 812, 814, 816, and 818, respectively.As a result, these nanotubes may be individually insulated such thatmultiple electrical signals may be transmitted through communicationslink 800.

If the different nanotubes are not individually insulated, then thenanotubes may carry the same electrical signal, but with reducedresistance, more electron flow, and higher power. Further, when thenanotubes are not individually insulated, different optical signals maystill propagate through the channels of the different nanotubes.

Additionally, communications link 800 also includes cover 832. Cover 832may be a protective cover and also may provide insulating propertiesdepending on the particular implementation.

Turning now to FIG. 9, an illustration of an end of a communicationslink is depicted in accordance with an illustrative embodiment. In thisillustrative example, end 802 of communications link 800 is shown.

With reference now to FIG. 10, an illustration of different orientationsfor layers of carbon that may be selected to form different types ofnanotubes is depicted in accordance with an illustrative embodiment. Inthis illustrative example, sheet 1000 is a sheet of carbon. Thearrangement of the carbon atoms in this sheet is in the form ofgraphene.

As depicted, layer 1002 may be formed from a portion of sheet 1000.Layer 1002 is an example of a layer that may be in number of layers ofcarbon 302 that form tube 300 in FIG. 3.

Layer 1004 also may be formed from sheet 1000. Layer 1004 may be formedinto a tube that forms a zigzag nanotube in this illustrative example.

As another example, layer 1006 is another layer that may be formed fromsheet 1000. Layer 1006 has an orientation that may be used to form anarmchair nanotube. Of course, other orientations other than thoseillustrated here with different angles may be selected depending on theparticular implementation.

Turning now to FIG. 11, an illustration of a multi-walled nanotube isdepicted in accordance with an illustrative embodiment. In thisillustrative example, nanotube 1100 may be comprised of layers of carbon1102. These different layers of carbon form walls 1104. In particular,layers 1100 include layer 1106, layer 1108, and layer 1110. These layersform wall 1112, wall 1114, and wall 1116 for tube 1100.

Turning now to FIG. 12, an illustration of devices connected to eachother through nanotubes is depicted in accordance with an illustrativeembodiment. In this depicted example, device 1200 and device 1202 maycommunicate with each other over communications link 1204 andcommunications link 1206. Communications link 1204 and communicationslink 1206 are formed from nanotubes 1207.

As depicted, communications link 1204 comprises tubes 1208, 1210, 1212,1214, 1216, 1218, and 1220. Communications link 1206 comprises nanotubes1222, 1224, 1226, 1228, 1230, 1232, and 1234.

As depicted, device 1200 includes transmitter 1240, receiver 1242, andpower supply 1244. Device 1202 includes transmitter 1246, receiver 1248,and power supply 1245.

Transmitter 1240 and transmitter 1246 may be configured to transmitoptical signals, electrical signals, or both optical signals andelectrical signals. These transmitters may include an optical emittersuch as a light emitting diode, a laser, and other suitable opticaldevices for generating optical signals. The transmitters also mayinclude circuits configured to generate electrical signals.

These circuits in the transmitters may include, for example, analog todigital circuits, digital to analog circuits, voice communicationscircuits, video communications circuits, signaling circuits,multiplexer/demultiplexer circuits, radio-frequency circuits, controlcircuits, sensors, magnetic-electrical inductors, solar panels, powerconversion circuits, direct current circuits, alternating currentcircuits, and any other suitable circuits.

Receiver 1242 and receiver 1248 are configured to receive opticalsignals, electrical signals, or both optical signals and electricalsignals. These receivers may include a photo diode, a charge-coupleddevice, a photo multiplier, and other suitable optical signal detectors.The receivers also may include circuits configured to receive electricalsignals.

These circuits in the receivers may include, for example, analog todigital circuits, digital to analog circuits, voice communicationcircuits, video communications circuits, signaling circuits,multiplexer/demultiplexer circuits, radio-frequency circuits, controlcircuits, sensor receiver circuits, electro-magnetic inductors, heatgenerators, power conversion circuits, direct current loads, alternatingcurrent loads, and any other suitable circuits.

Power supply 1244 is configured to generate electrical signals that maybe used to power circuits. Power supply 1244 may be, for example, adirect current power supply, an alternating power supply, or some othersuitable type of power supply device.

Power supply 1245 is configured to receive power generated by powersupply 1244. Power supply 1245 includes circuits used to distribute theelectrical signals to circuits within device 1202.

Of course, power supply 1245 also may be used to generate electricalsignals used to power circuits outside of device 1202. Additionally,power supply 1244 also may be configured to receive electrical signalsgenerated by power supply 1245 and distribute those electrical signalsto circuits within device 1200.

In this illustrative example, transmitter 1240 may transmit photons intoone or more of the nanotubes in communications link 1204. These photonsmay be received by receiver 1248 in device 1202 using one or more ofnanotubes 1207 in communications link 1204.

In a similar fashion, transmitter 1240 also may send electrical signalsthrough one or more of nanotubes 1207 in communications link 1204. Theseelectrical signals may be received by receiver 1200. In someillustrative examples, the electrical signals sent through one or moreof nanotubes 1207 in communications link 1204 may be used to power oneor more circuits in device 1202. For example, the electrical signals maybe used to power circuits in receiver 1248, transmitter 1246, or both ofthese circuits. In this illustrative example, power supply 1244 maygenerate electrical signals sent through one or more of tubes 1207 incommunications link 1204 to receiver 1248.

Turning now to FIG. 13, an illustration of devices powered by HallEffect devices is depicted in accordance with an illustrativeembodiment. In this illustrative example, transmitter 1300 and receiver1302 may communicate with each other using communications link 1304.

Transmitter 1300 is an example of an implementation for transmitter 404in FIG. 4. Receiver 1302 is an example of an implementation of receiver402 in FIG. 4.

In this illustrative example, transmitter 1300 includes amplifier 1306and optical emitter 1308. Amplifier 1306 is configured to amplify inputsignals for transmission to receiver 1302. These input signals areelectrical signals in these illustrative examples. Optical emitter 1308is configured to transmit optical signals through tube 1310 incommunications link 1304 in response to receiving the input signals fromamplifier 1306.

Receiver 1302 is configured to receive the optical signals. Receiver1302 includes optical detector 1312, decoder 1314, and buffer 1316.

In this illustrative example, current source 1318 is connected to tube1310 and is configured to send electrical signal 1320 through tube 1310.Electrical signal 1320 has a current level in these illustrativeexamples.

Further, magnetic field generator 1322 may be used to generate power forcircuits within transmitter 1300. Magnetic field generator 1334generates a magnetic field.

In this illustrative example, the magnetic field generated by magneticfield generator 1322 may cause voltage difference 1324 to occur aselectrical signal 1320 travels through tube 1310. The magnetic field isapplied to electrical signal 1320.

Voltage difference 1324 is a voltage difference between side 1326 andside 1328 of tube 1310. This voltage difference may extend to side 1330and side 1332 of communications link 1304. Connections from side 1330and side 1332 may be made to amplifier 1306 to supply power to amplifier1306 and optical emitter 1308.

In a similar fashion, magnetic field generator 1334 may be configured togenerate power for circuits within receiver 1302. Magnetic fieldgenerator 1334 generates a magnetic field. The magnetic field may causevoltage difference 1324 to occur when electrical signal 1320 passesthrough tube 1310. The magnetic field is applied to electrical signal1320.

This voltage difference may be used to provide power to receiver 1302.In this illustrative example, optical detector 1312, decoder 1314, andother electronics 1316 are connected to side 1330 and side 1332 of tube1310.

The illustration of the carbon layer, the nanotube, the communicationslink, and the devices in FIGS. 5-13 are not meant to imply physical orarchitectural limitations to the manner in which an illustrativeembodiment may be implemented. For example, in some illustrativeexamples, communications link 800, communications link 1304, or bothcommunications link 800 and communications link 1304 may be comprised ofa single nanotube rather than multiple nanotubes.

In still other illustrative examples, additional layers may be presentin nanotube 602 in addition to layer of graphene 502. For example, oneor more additional layers of graphene may be present in forming nanotube602.

FIGS. 5-13 may be combined with components in FIGS. 1-4, used withcomponents in FIGS. 1-4, or a combination of the two. Additionally, someof the components in FIGS. 5-13 may be illustrative examples of howcomponents shown in block form in FIGS. 1-4 can be implemented asphysical structures.

With reference now to FIG. 14, an illustration of a flowchart of aprocess for transmitting signals is depicted in accordance with anillustrative embodiment. The process illustrated in FIG. 14 may beimplemented in information environment 100 in FIG. 1. In particular, theprocess may be implemented in communications links 110 formed usingtubes, such as tube 300 in FIG. 3.

The process begins by a first device encoding information into at leastone of an optical signal and an electrical signal (operation 1400). Thefirst device may be a device in devices 108 in FIG. 1.

The process then transmits at least one of the optical signal and theelectrical signal using a tube comprised of a number of layers of carbon(operation 1402). This tube has a number of optical propertiesconfigured to propagate the optical signal and a number of electricalproperties configured to conduct the electrical signal.

The optical signal, the electrical signal, or both are received andprocessed by a second device (operation 1404) with the processterminating thereafter. In operation 1404, the second device may decodeor use the information encoded in at least one of the optical signal andthe electrical signal. In other illustrative examples, the second devicemay amplify at least one of the optical signal and the electrical signaland retransmit these signals to yet another device. In other words, thesecond device may operate as a repeater or an amplifier. Further, thisrepeater or amplifier may be purely electrical, purely optical, or useoptical-electrical or electro-optical conversion.

In still other illustrative examples, the first device may transmit theelectrical signal as a power signal. The second device may receive anduse the electrical signal as a power source for the different circuitswithin the second device.

Turning now to FIG. 15, an illustration of a flowchart of a process fortransmitting a signal is depicted in accordance with an illustrativeembodiment. The process illustrated in FIG. 15 may be implemented in aninformation environment, such as information environment 100 in FIG. 1.In particular, this process may be implemented using device 400 in FIG.4. More specifically, this process may be implemented using transmitter404 in device 400.

The process begins by connecting a nanotube to a transmitter in a device(operation 1500). The process then transmits a number of signals usingthe nanotube (operation 1502) with the process terminating thereafter.In this illustrative example, operation 1500 may include transmitting atleast one of an optical signal and an electrical signal. In theseillustrative examples, both an optical signal and an electrical signalmay be transmitted at the same time using the nanotube.

Turning now to FIG. 16, an illustration of a flowchart of a process fortransmitting a signal is depicted in accordance with an illustrativeembodiment. The process illustrated in FIG. 16 may be implemented in aninformation environment, such as information environment 100 in FIG. 1.In particular, this process may be implemented using device 400 in FIG.4. More specifically, this process may be implemented using receiver 402in device 400.

The process begins by connecting a nanotube to a receiver in a device(operation 1600). The process then receives a number of signals usingthe nanotube (operation 1602) with the process terminating thereafter.In this illustrative example, operation 1600 may include transmitting atleast one of an optical signal and an electrical signal. In theseillustrative examples, both an optical signal and an electrical signalmay be transmitted at the same time using the nanotube.

The flowcharts and block diagrams in the different depicted embodimentsillustrate the architecture, functionality, and operation of somepossible implementations of apparatus and methods in an illustrativeembodiment. In this regard, each block in the flowcharts or blockdiagrams may represent a module, segment, function, and/or a portion ofan operation or step. For example, one or more of the blocks may beimplemented as program code, in hardware, or a combination of theprogram code and hardware. When implemented in hardware, the hardwaremay, for example, take the form of integrated circuits that aremanufactured or configured to perform one or more operations in theflowcharts or block diagrams.

In some alternative implementations of an illustrative embodiment, thefunction or functions noted in the blocks may occur out of the ordernoted in the figures. For example, in some cases, two blocks shown insuccession may be executed substantially concurrently, or the blocks maysometimes be performed in the reverse order, depending upon thefunctionality involved. Also, other blocks may be added in addition tothe illustrated blocks in a flowchart or block diagram.

For example, the operations in FIGS. 15 and 16 may be combined when thedevice includes a transceiver. A transceiver may send a signal whilereceiving a signal at the same time. For example, an optical signal maybe transmitted while an electrical signal is received.

Thus, the illustrative embodiments provide a method and apparatus fortransmitting optical signals and electrical signals. These signals maybe transmitted at the same time through the same tube in acommunications link. The illustrative examples employ tubes formed froma number of layers of carbon in which the structure of the number oflayers of carbon is selected to have optical properties for propagatingphotons and electrical properties for conducting electrons.

As described above, these tubes may be nanotubes and the number oflayers of carbon may be a number of layers of graphene. By usingnanotubes in communications links, the size and weight of communicationslinks may be reduced. As a result, the size and weight of acommunications system that transmits information and power may bereduced as compared to currently used optical communications links andwire links. This reduction in size and weight may increase the ease atwhich size, weight, power and other constraints in aircraft or otherplatforms may be met as compared to using metal wires and/or opticalfibers.

Further, the number of nanotubes in an area, with the increased surfacearea “skin effect” for electrons will greatly decrease the conductivity,and greatly increase the electrical power that can be transferred.Similarly, the increased number of nanotubes will greatly increase thenumber of individual optical transmission media, and therefore greatlyincrease the bandwidth of the medium.

Additionally, the illustrative embodiments also provide devices that areconfigured to communicate using the tubes. These devices may communicateusing at least one of optical signals and electrical signals. In theillustrative examples, these signals may encode information. Further, insome illustrative examples, the electrical signals may also be used toprovide power to the circuits in the different devices.

The description of the different illustrative embodiments has beenpresented for purposes of illustration and description, and is notintended to be exhaustive or limited to the embodiments in the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art.

For example, although some of the illustrative examples show the use ofelectrical signals to supply power, the optical signals also may be usedto supply power. When optical signals are used to supply power, circuitsand other devices may be included to generate optical signals that areconfigured to be used to power devices as well as circuits and otherdevices that may be included to receive and use the optical energy forsupplying power.

Further, different illustrative embodiments may provide differentfeatures as compared to other desirable embodiments. The embodiment orembodiments selected are chosen and described in order to best explainthe principles of the embodiments, the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. An apparatus comprising: a tube comprised of alayer of carbon forming a wall of the tube, wherein the layer of carbonhas a number of optical properties configured to propagate an opticalsignal within a channel in the tube and a number of electricalproperties configured to conduct an electrical signal along a surface ofthe wall of the tube; and an insulating sheath covering an outer surfaceof the wall of the tube; wherein the tube forms a hollow core opticalfiber; wherein the tube is configured to transmit information in atleast one of the optical signal and the electrical signal; wherein thetube and a number of additional tubes comprised of a number ofadditional layers of carbon form a communications link; and wherein theinsulating sheath: provides an index of refraction for the opticalsignal that passes through the wall of the tube, and provides opticalabsorption of stray photons that pass through the wall at an incidencethat is greater than the index of refraction.
 2. The apparatus of claim1, wherein the tube is one of a plurality of tubes; wherein each of thetubes is covered by an insulating sheath; and wherein the apparatusfurther comprises a cover surrounding the insulating sheathes of theplurality of tubes, the cover insulating and protecting the plurality oftubes.
 3. The apparatus of claim 1, wherein the layer of carbon is alayer of graphene.
 4. The apparatus of claim 1, wherein the tube is acarbon nanotube.
 5. The apparatus of claim 1, wherein the tube isconfigured to transmit information using the optical signal and powerusing the electrical signal.
 6. The apparatus of claim 1, wherein alength of the tube is at least about 18.5 centimeters.
 7. Acommunications system comprising: a network comprised of graphenenanotubes, the graphene nanotubes comprising one or more each of: a tubecomprised of a layer of carbon forming a wall of the tube, wherein thelayer of carbon has a number of optical properties configured topropagate an optical signal within a channel in the tube and a number ofelectrical properties configured to conduct an electrical signal along asurface of the wall of the tube; an insulating sheath covering an outersurface of the wall of the tube; wherein the tube forms a hollow coreoptical fiber; and a number of devices configured to exchangeinformation using at least one of the optical signals and the electricalsignals; wherein the tube is configured to transmit information in atleast one of the optical signal and the electrical signal; wherein thetube and a number of additional tubes comprised of a number ofadditional layers of carbon form a communications link; and wherein theinsulating sheath: provides an index of refraction for the opticalsignal that passes through the wall of the tube, and provides opticalabsorption of stray photons that pass through the wall at an incidencethat is greater than the index of refraction.
 8. The communicationssystem of claim 7, wherein a portion of the number of devices receivespower from the network over the graphene nanotubes.
 9. A method fortransmitting signals comprising: transmitting at least one of an opticalsignal and an electrical signal using a tube comprised of a layer ofcarbon forming a wall of the tube, wherein the layer of carbon has anumber of optical properties configured to propagate an optical signalwithin a channel in the tube and a number of electrical propertiesconfigured to conduct an electrical signal along a surface of the wallof the tube; and an insulating sheath covering an outer surface of thewall of the tube; wherein the tube forms a hollow core optical fiber;wherein the tube is configured to transmit information in at least oneof the optical signal and the electrical signal; wherein the tube and anumber of additional tubes comprised of a number of additional layers ofcarbon form a communications link; and wherein the insulating sheath:provides an index of refraction for the optical signal that passesthrough the wall of the tube, and provides optical absorption of strayphotons that pass through the wall at an incidence that is greater thanthe index of refraction.
 10. The method of claim 9 further comprising:encoding information into the at least one of the optical signal and theelectrical signal.
 11. The method of claim 9 further comprisingsupplying power to a device using at least one of the optical signal andthe electrical signal.
 12. The method of claim 9, wherein the layer ofcarbon is a layer of graphene.